Akai VS3 VCR - turns on and enters REC mode without tape
Franc Zabkar
on (from standby mode) and begins to play without a tape being
present. It appears to be in REC mode when doing this. Timer recording
is not programmed. The customer says that the unit will sometimes
rewind or fast forward.
I have changed the power supply PCB, which also has an MB88401 uP.
Since then the unit appears to misbehave less frequently. It now
switches (by itself) to power on mode but does not play.
Can anyone offer any advice?
-- Franc Zabkar
Please remove one 'g' from my address when replying by email.
Allan
thing, something else fails..
Franc Zabkar wrote in message <365e715...@news.bigpond.com>...
Farmer
>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>on (from standby mode) and begins to play without a tape being
>present. It appears to be in REC mode when doing this. Timer recording
>is not programmed. The customer says that the unit will sometimes
>rewind or fast forward.
>
>I have changed the power supply PCB, which also has an MB88401 uP.
>Since then the unit appears to misbehave less frequently. It now
>switches (by itself) to power on mode but does not play.
>
>Can anyone offer any advice?
>
>
>-- Franc Zabkar
I had one of these recorders once before it got stolen and had the
same problem. On mine it was caused by sunlight falling on the remote
sensor, Dunno if this might help.
--------------------
Have a nice day
Farmer 3:16
dronek
Zabkar) wrote:
>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>on (from standby mode) and begins to play without a tape being
>present. It appears to be in REC mode when doing this. Timer recording
>is not programmed. The customer says that the unit will sometimes
>rewind or fast forward.
>
This might seem silly but is someone using a remote when these things
happen? I have an Akai vs15ea and the exact things happen to it when
i use another remote (tv, stereo ect) its usualy the last function
used by the vcr remote. ive pressed power on the vcr, then the tv and
the vcr has turned off. or it starts recording when i change channel
on foxtel. any remote can do it. piece of crap! i think new
machines have an encoded remote signal so this won't happen.
very anoying when your recording something and you change the volume
on the tv and the vcr starts rewinding of its own free will.
anyway its possible!
Ken
David J Kilpatrick
>
> Don't waste your time on these 10 Year old relich's. As soon as you fix one
> thing, something else fails..
>
Only because people give up on them all too soon ... sure it's not worth
reparing from a commercial point of view (labour charges etc..) but why
the hell do so many tech's these days have the mentality of 'if it takes
more than 10 minutes, trash it?'. It's like taking your car to the
mechanic and having him say 'you're spark plugs are dud - better buy a
new car'.
I have a 8 year old Phillips Stereo VCR (heavy old thing) that after
sorting through a few niggling problems (tuner going of station,
intermittant stopping etc..) it now produces an excellent picture. And
no doubt due to it's robust construction, it will still be going long
after today's $250 cheapie Chinese crap thing will have broken some 50
cent-no-longer-availble-after-6-months-part.
Anyhow .. this doesn't help Frank at all (Akai's are only a bastard to
those who let them be bastards to them .. much like Sony TV's). I have
seen these machines do odd things when another remote control is pointed
at them. Check the power supply rails with a CRO for excessive ripple
too...
If you want to ask further questions, just email me...
--
===================================================
David J Kilpatrick - - - braind...@mpx.com.au
ICQ 8233607 - - - - - - - (remove 'brain' to reply)
Franc Zabkar
composed:
>Franc...@biggpond.com (Franc Zabkar) wrote:
>
>>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>>on (from standby mode) and begins to play without a tape being
>>present. It appears to be in REC mode when doing this. Timer recording
>>is not programmed. The customer says that the unit will sometimes
>>rewind or fast forward.
>>
>>I have changed the power supply PCB, which also has an MB88401 uP.
>>Since then the unit appears to misbehave less frequently. It now
>>switches (by itself) to power on mode but does not play.
>>
>>Can anyone offer any advice?
>>
>>
>>-- Franc Zabkar
>I had one of these recorders once before it got stolen and had the
>same problem. On mine it was caused by sunlight falling on the remote
>sensor, Dunno if this might help.
Nice try but not possible in this case because:
(1) The unit misbehaves at night.
(2) There is no tape in the machine.
Franc Zabkar
composed:
>On Fri, 27 Nov 1998 09:35:43 GMT, Franc...@biggpond.com (Franc
>Zabkar) wrote:
>
>>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>>on (from standby mode) and begins to play without a tape being
>>present. It appears to be in REC mode when doing this. Timer recording
>>is not programmed. The customer says that the unit will sometimes
>>rewind or fast forward.
>>
>This might seem silly but is someone using a remote when these things
>happen? I have an Akai vs15ea and the exact things happen to it when
>i use another remote (tv, stereo ect) its usualy the last function
>used by the vcr remote. ive pressed power on the vcr, then the tv and
>the vcr has turned off. or it starts recording when i change channel
>on foxtel. any remote can do it. piece of crap! i think new
>machines have an encoded remote signal so this won't happen.
This machine misbehaves when unattended. Even if another remote
control unit were available, there is no tape in the machine when it
misbehaves. Hence it is not possible for it to be commanded to play a
tape.
Farmer
>On Fri, 27 Nov 1998 18:33:52 GMT, Farmer put finger to keyboard and
>composed:
>
>>Franc...@biggpond.com (Franc Zabkar) wrote:
>>
>>>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>>>on (from standby mode) and begins to play without a tape being
>>>present. It appears to be in REC mode when doing this. Timer recording
>>>is not programmed. The customer says that the unit will sometimes
>>>rewind or fast forward.
>>>
>>>I have changed the power supply PCB, which also has an MB88401 uP.
>>>Since then the unit appears to misbehave less frequently. It now
>>>switches (by itself) to power on mode but does not play.
>>>
>>>Can anyone offer any advice?
>>>
>>>
>>>-- Franc Zabkar
>>I had one of these recorders once before it got stolen and had the
>>same problem. On mine it was caused by sunlight falling on the remote
>>sensor, Dunno if this might help.
>
>Nice try but not possible in this case because:
>
>(1) The unit misbehaves at night.
>(2) There is no tape in the machine.
>
Fair enough but it was strange on my machine too, It used to record
the picture but not the sound and it wasn't fussy about whether there
was a tape in it or not. Real twilight zone stuff until i stopped the
afternoon sun hitting it.
Maybe the remote sensor is sending weird signals to the VCR ?
Michael Caplan
full play or record suggested that the syscon was malfunctioning -- it
was starting the set on its own and the end of tape detection system
was not working --it should have stopped the operation as soon as it
started. Now, with the power supply replaced, the symptom is somewhat
reduced -- the set still turns itself on but does not go into any
operating mode. This result from changing the power supply suggests
to me that the problem might still be power source related --
something that's common with the power supply itself and also the
syscon.
There are usually filter caps on the power supply lines throughout the
set (i.e. not just at the power supply board itself). One or more of
these might be open. As a result, noise/ripple is getting onto that
power supply bus at a distance from the power supply itself and is
being carried throughout the set including to the microprocessor where
it upsets its operation. The new power supply board with its new
caps, reduced the offending signal, but it cannot eliminate it --
that's why the filter caps are strategically located throughout the
set.
It's a tough one to isolate without the schematic. You might be able
to follow some of the power supply lines/pcb traces, or identify the
Vcc and B+ lines at the ICs where you can scope what's on them.
Otherwise you might have to individually check each cap until the bad
one is found (probably an electrolytic but I have had more than one
instance where an open disc type cap was the problem). Hope this
helps.
Michael Caplan CET
On Fri, 27 Nov 1998 09:35:43 GMT, Franc...@biggpond.com (Franc
Zabkar) wrote:
>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>on (from standby mode) and begins to play without a tape being
>present. It appears to be in REC mode when doing this. Timer recording
>is not programmed. The customer says that the unit will sometimes
>rewind or fast forward.
>
>I have changed the power supply PCB, which also has an MB88401 uP.
>Since then the unit appears to misbehave less frequently. It now
>switches (by itself) to power on mode but does not play.
>
>Can anyone offer any advice?
>
>
>-- Franc Zabkar
>
Allan
David J Kilpatrick wrote in message <365F61...@mpx.com.au>...
>Allan wrote:
>>
>> Don't waste your time on these 10 Year old relich's. As soon as you fix
one
>> thing, something else fails..
>>
>*snip*
>
>Only because people give up on them all too soon ... sure it's not worth
>reparing from a commercial point of view (labour charges etc..) but why
>the hell do so many tech's these days have the mentality of 'if it takes
>more than 10 minutes, trash it?'. It's like taking your car to the
>mechanic and having him say 'you're spark plugs are dud - better buy a
>new car'.
Yes but the rest of the Car is falling to bits, the Motor is on its last
legs , the body of full of rust and
the diff and electrics are all worn and about to fail, and the ONLY thing
YOU as a customer sees as being wrong is it needs a New Spark PLUG!..
And if we do replace the Spark Plug you will bring it back or winge to all
your mates that now the Diff is gone, the wiring it faulty and the motor has
failed, and there was nothing wrong withit before I took it to the repairer.
Don't LAUGH it happens! and it does not matter how many times you tell them
before you replace THOSE spark plugs, there is aways those fools who don't
LISTEN!..
>
>I have a 8 year old Phillips Stereo VCR (heavy old thing) that after
>sorting through a few niggling problems (tuner going of station,
>intermittant stopping etc..) it now produces an excellent picture. And
>no doubt due to it's robust construction, it will still be going long
>after today's $250 cheapie Chinese crap thing will have broken some 50
>cent-no-longer-availble-after-6-months-part.
>
>Anyhow .. this doesn't help Frank at all (Akai's are only a bastard to
>those who let them be bastards to them .. much like Sony TV's).
Frank you coudl check the CPU on the Front panel. It contols IR and Button
selection. Maybe it is sending Scrambled Info to the Main/Servo CPU?
The fault is more likely to be a CPU fault.
You should be able to get a Wrecked machine from a Repairer for cheap
parts..
Allan
Henry
Farmer wrote in message <3662c5af...@news.ozemail.com.au>...
>Franc...@biggpond.com (Franc Zabkar) wrote:
>>On Fri, 27 Nov 1998 18:33:52 GMT, Farmer put finger to keyboard and
>>composed:
>>>Franc...@biggpond.com (Franc Zabkar) wrote:
>>>>I am troubleshooting an Akai VS3 VCR which intermittently turns itself
>>>>on (from standby mode) and begins to play without a tape being
>>>>present. It appears to be in REC mode when doing this. Timer recording
>>>>is not programmed. The customer says that the unit will sometimes
>>>>rewind or fast forward.
>>>>I have changed the power supply PCB, which also has an MB88401 uP.
>>>>Since then the unit appears to misbehave less frequently. It now
>>>>switches (by itself) to power on mode but does not play.
>>>>Can anyone offer any advice?
>>>>-- Franc Zabkar
>>>I had one of these recorders once before it got stolen and had the
>>>same problem. On mine it was caused by sunlight falling on the remote
>>>sensor, Dunno if this might help.
>>Nice try but not possible in this case because:
>>(1) The unit misbehaves at night.
>>(2) There is no tape in the machine.
>Fair enough but it was strange on my machine too, It used to record
>the picture but not the sound and it wasn't fussy about whether there
>was a tape in it or not. Real twilight zone stuff until i stopped the
>afternoon sun hitting it.
>Maybe the remote sensor is sending weird signals to the VCR ?
It seems likely in one case that the afternoon sun may be heating the VCR
and that above some critical temperature something starts going wrong with
some of the electronics inside. (Maybe power supply goes unstable, or
micro-controller goes apeshit.) Try putting it near a heater (not too hot!)
and see if you can cause it to misbehave.
As for the other unit, which misbehaves at night : Try the heating/cooling
experiment, and maybe try putting some masking tape over the RC sensor.
Maybe it's picking up infra-red signals from somewhere...
davidrs...@googlemail.com
On Friday, 27 November 1998 08:00:00 UTC, Franc Zabkar wrote:
> I am troubleshooting an Akai VS3 VCR which intermittently turns itself
> on (from standby mode) and begins to play without a tape being
> present. It appears to be in REC mode when doing this. Timer recording
> is not programmed. The customer says that the unit will sometimes
> rewind or fast forward.
>
> I have changed the power supply PCB, which also has an MB88401 uP.
> Since then the unit appears to misbehave less frequently. It now
> switches (by itself) to power on mode but does not play.
>
> Can anyone offer any advice?
>
>
> -- Franc Zabkar
>