Bad Hardrock 500 Power Board?

[K5RHD Randy Diddel]

EDIT: I cannot seem to get any photos attached. I will put one in a reply to this thread...

Hi,

Earlier this weekend, I was using the amp without issue. Today, I turned the amp on and had no power out with PTT enabled. The VDD on the panel shows 0 volts. I got out the Fluke and opened the bottom of the 500. All three MeanWells have ~19.3 volts out. On the amp out, there are 0 volts out. So, the issue is somewhere on that board. I have attached some pics but cannot see anything wrong. 

Jim, do you still have any spare boards? Can I send you the board to look at? Does anyone else see anything I can't?

Thanks and 73,

K5RHD

/randy

[K5RHD Randy Diddel]

[K5RHD Randy Diddel]

[jcve...@gmail.com]

Hi Randy,

There's a LED labeled HV_ON near the big cap; is it on?

We need to know if the control system is telling the power to be on and it's not (the switch is bad) or the control system isn't turning on the power (some safety condition is having an issue).

There's a high power MOSFET on the power board (Q201) that can cut the 58V to the VRF2933s is milliseconds if an issue is detected, unfortunately the VRF2933s can be destroyed in microseconds under the right (wrong) conditions. But you never know what you prevent so I'm sure that it has saved a MOSFET or two.

If the HV_ON LED is lit then replace Q201, Q202, D201, D202, R201, R202 and everything should work again. If the HV_ON LED is off, try grounding the junction of R202 and Q202's drain which should turn the power on if everything in the switch is working as expected.

Unfortunately, there aren't any spare boards, I've sold every spare parts that I have and I just sent a ham the gerbers so he can make his own boards.

73,

Jim WA2EUJ

[K5RHD Randy Diddel]

Hey all,

I did some basic testing that was suggested and cannot determine which part(s) have failed.

I do not have the ability to solder SMDs and the time to replace all the parts on the power board. As such, I am offering up my HR500 up for sale to someone who can revive it. It will come with a KX3 harness as well as a IC-705 bluetooth interface.

Back story:  The amp and ATU were working when I turned it off for the day. The following day, it would not power up. All three Meanwell power supplies put out full power (~19.5V each). There is no green LED on the HV_ON as noted above.  

Asking $1200.00 shipped and I am firm on the price. If I do not sell it, it can serve as a door stop in my shack. I have too much invested in the amp to take less than asking price.

Contact me off list if interested.

73

K5RHD

/randy

[K5RHD Randy Diddel]

Tha amp is spoken for and has been SOLD.

/randy