[Top] [All Lists]

Re: [Amps] Alpha 87A - strange power related issue

To: <>
Subject: Re: [Amps] Alpha 87A - strange power related issue
From: <>
Date: Mon, 10 Oct 2022 10:00:07 -0400
List-post: <>
Does that perhaps use solid state switches to turn on the main power?  I have 
seen them (in a different amp) get leaky which produced a low control voltage 
when they were supposed to be off, something like that on a digitally 
controlled amp could produce flakey displays or maybe give enough voltage to 
run the fan.

David Robbins K1TTT
AR-Cluster node: telnet://

-----Original Message-----
From: Amps <> On Behalf Of gudguyham--- via Amps
Sent: Monday, October 10, 2022 09:52
To:; 'Eric Dobrowansky' <>;
Subject: Re: [Amps] Alpha 87A - strange power related issue

Eric, most likely you have a problem on the primary start up board. This is 
where the step start is and all the primary wiring gets routed.  Often times 
the sticky tape gets conductive over time and it shorts out the blower traces 
and blows them open.  It’s possible there’s a problem with the step start 
relay.  It’s most likely a problem in this area.  Don’t discount a problem with 
those push on/off switches on the front panel of course.  But do remove that 
primary board and investigate it.  It removes very easily.  Here’s a step by 
step procedure.  1. Pull the transformer plug from the board.2. Remove all 
transformer wires from boards 3. Pull out transformer.4. Remove two screws near 
the two fuses that hold start assembly.5. Remove one nut holding one bracket on 
opposite side of variable cap middle divider. The board comes right out along 
with the AC cord, remove plug if you have to.
Once you get that board out there’s your relay on there etc.  you’ll see that 
sticky tape that hold down the electrolytic cap.  It’s best to remove that tape 
because it will create problems if it hasn’t already.   Just let the cap 
support itself that’s fine.  If you email me personally I can send you some 
photos.  Lou

Sent from the all new AOL app for iOS

On Sunday, October 9, 2022, 8:42 PM, <> 


There is an 87A Email Group.  You can find them here:

You will have to sign up for an "" account and after that you should 
be able to query for the Alpha 87A group and request access.

Hope this helps.

Thank you,


-----Original Message-----
From: Amps <> On Behalf Of Eric Dobrowansky
Sent: Sunday, October 9, 2022 7:26 PM
Subject: [Amps] Alpha 87A - strange power related issue

It's been a long time, and I'm not sure if there is a dedicated Alpha 87A 
related mail list in existence any longer, so I will go ahead and ask here.

I have an 87A that started exhibiting a strange problem.

When the amp is plugged in, the blower automatically starts, and various band 
and segment LEDs illuminate, but the amp does not start up. The LEDs which 
illuminate vary each time the amp is plugged in. 

If I try to push the POWER OFF switch, the amp will turn off the blower and 
LEDs, but as soon as I release the switch, it returns to the state where the 
LEDs and blower are on.

If I push the POWER ON switch, the amp starts up normally. The amp works fine 
once it completes the warm-up period. 

If I then press the POWER OFF button to turn the amp off from when it is fully 
running, it shuts down properly. IE - all the LEDs turn off, and the blower 

However, if I leave it plugged in, out of nowhere sometime later the above 
symptom repeats, and I have to pull the AC plug to get it to shut down 

Any recommendations as to where to start troubleshooting?  Maybe a cap going 
bad somewhere is pulling down a particular control circuit?


Amps mailing list

This email has been checked for viruses by Avast antivirus software.
Amps mailing list

Amps mailing list

Amps mailing list
<Prev in Thread] Current Thread [Next in Thread>