Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Need a service manual SENNHEISER UPM 550-1
219 views
Skip to first unread message
Bo-Lennart
Mar 7, 2018, 12:25:00 PM3/7/18
to
Have a SENNHEISER UPM 550-1 (audio level-meter). My problem is that -14Vdc from the power-supply board is goes upp and down to nearly 0 Vdc. If I take out the board labeled B15, the -14Vdc is stable. And I can use the instrument as a AC-rms voltmeter. No problem. But something happen the I re-plug the board B15. The B15-board have something to do with the CCIR-filter (I guess). But I need a service manual to find out. Maybe someone out there, know exactly what's wrong here.
Best regards from SWEDEN
Bo-Lennart Karlsson
Falun, SWEDEN
Best regards from SWEDEN
Bo-Lennart Karlsson
Falun, SWEDEN
Phil Allison
Mar 8, 2018, 12:35:58 AM3/8/18
to
Bo-Lennart wrote:
------------------
> Have a SENNHEISER UPM 550-1 (audio level-meter). My problem is that
> -14Vdc from the power-supply board is goes upp and down to nearly 0 Vdc.
> If I take out the board labeled B15, the -14Vdc is stable. And I can use
> the instrument as a AC-rms voltmeter. No problem. But something happen
> the I re-plug the board B15. The B15-board have something to do with
> the CCIR-filter (I guess).
> But I need a service manual to find out.
** I doubt that it would be much use.
Some component pulling current from the -14V rail to ground on that PCB is drawing way too much. Likely culprits include zener diodes, bead tantalum electros and low voltage ceramic caps.
However, I would clean and inspect the board first; a loose screw, tiny solder blob or metal fragment would do the same thing if lodged in a bad place.
If you power the -14V from a bench supply, localised heating or a bit of smoke might direct your attention to the right area.
.... Phil
------------------
> Have a SENNHEISER UPM 550-1 (audio level-meter). My problem is that
> -14Vdc from the power-supply board is goes upp and down to nearly 0 Vdc.
> If I take out the board labeled B15, the -14Vdc is stable. And I can use
> the instrument as a AC-rms voltmeter. No problem. But something happen
> the I re-plug the board B15. The B15-board have something to do with
> the CCIR-filter (I guess).
> But I need a service manual to find out.
Some component pulling current from the -14V rail to ground on that PCB is drawing way too much. Likely culprits include zener diodes, bead tantalum electros and low voltage ceramic caps.
However, I would clean and inspect the board first; a loose screw, tiny solder blob or metal fragment would do the same thing if lodged in a bad place.
If you power the -14V from a bench supply, localised heating or a bit of smoke might direct your attention to the right area.
.... Phil
Message has been deleted
Bo-Lennart
Mar 13, 2018, 4:07:44 AM3/13/18
to
Thanks for Your reply.
Some nice guy send me schematics of the power supply board (B16) and board B15.
Was that You???
I checked the Board B15 and found 3 shorted tantal-capacitors, C551, 548, 550.
Changed these capacitors solved the problem.
But there are some more problem with the instrument. In the 3 lowest range 300, 100, 30 micro Volt, the pointer of the movement is not stable. So I will
continue foult-finding. The final problem seems to be in the board B11. This board includes both divider and amplifier. With combinations of these divider and amplifier gives the 15 ranges of +50dB to -90dB.
OK, thanks once again for Your reply. I will continue the foult-finding.
serns...@gmail.com
Apr 30, 2020, 1:17:52 PM4/30/20
to
I'm looking for the service manual / schematics for the very same device. If anyone has them on hand and could forward them that would be reall helpful.
Thanks!
Arie de Muynck
May 1, 2020, 9:49:19 AM5/1/20
to
On 2020-04-30 19:17, serns...@gmail.com wrote:
>
> Hi Bo and everyone else reading,
>
> I'm looking for the service manual / schematics for the very same device. If anyone has them on hand and could forward them that would be reall helpful.
>
> Thanks!
>
For $5 the PDF is available:
>
> Hi Bo and everyone else reading,
>
> I'm looking for the service manual / schematics for the very same device. If anyone has them on hand and could forward them that would be reall helpful.
>
> Thanks!
>
https://www.manual-buddy.com/p/sennheiser/upm5501-service-manual.html
Bo-Lennart
May 1, 2020, 1:02:25 PM5/1/20
to
Bo-Lennart
May 1, 2020, 1:06:48 PM5/1/20
to
Den onsdag 7 mars 2018 kl. 18:25:00 UTC+1 skrev Bo-Lennart:
Bo-Lennart Karlsson
Falun, SWEDEN
Bo-Lennart
May 1, 2020, 1:29:25 PM5/1/20
to
Fox's Mercantile
May 1, 2020, 5:50:04 PM5/1/20
to
His email is: serns...@gmail.com
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
Bo-Lennart
May 2, 2020, 3:20:26 AM5/2/20
to
Den onsdag 7 mars 2018 kl. 18:25:00 UTC+1 skrev Bo-Lennart:
I try:serns...@gmail.com. Is'nt that the right address?
Bo-Lennart Karlsson
SWEDEN
Bo-Lennart
May 2, 2020, 3:39:57 AM5/2/20
to
Den onsdag 7 mars 2018 kl. 18:25:00 UTC+1 skrev Bo-Lennart:
Bo-Lennar...@Telia.com
serns...@gmail.com
May 2, 2020, 4:57:58 AM5/2/20
to
We spent some more time looking for the manual the other day and found it for sale on two websites. Since we got a bit impatient and it only was 5$, we just decided to buy it.
So, thanks again for offering your help! I hope you were successful with the work you were doing on your UPM 550
serns...@gmail.com
May 2, 2020, 5:01:43 AM5/2/20
to
0 new messages