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Peavey Valve King 100

Trying to see why guitar amp is not powering up. No light, sound or anything. Have amp a part and have started checking some things out. Anybody had any experience with troubleshooting these?
 

davenn

Moderator
Trying to see why guitar amp is not powering up. No light, sound or anything. Have amp a part and have started checking some things out. Anybody had any experience with troubleshooting these?

Hi there
welcome to EP :)

have you googled for any info on the amp .... schematic etc ?

could be a lot of things .... firstly, have you checked the fuse(s) ?
 
ZBZWpAvfbiX1ZUCT.jpg 20170403_120218.jpg 20170403_155239.jpg Thanks for reply...
Yes, I've Googled and found many things. Mostly people saying "take to service center".
The first thing I did was to check and make sure capacitors were drained.
Then, I found a circuitry diagram for a Peavey VK100 (212), but it seems a little different from what I have.


Firstly the circuitry schematic I have shows only (1) fuse inside, where this amp has (3).
Anyway, the outer fuse checks good, and the [3] inside fuses check good, [by way of checking with ohm meter showing continuity/'0'].
With my meter set to 20k ohms, and leads connected one to 'neutral' and the other to 'hot', [doesn't say 'line'], at the 'power input socket', when I turn the 'power' switch to 'on', there is no reading...with one lead still on 'line/hot', and touching the 204/fuse, meter goes to '0.01' reading...[I get this reading regardless if power switch is on or off]...when I touch P1 or P2, I'm assuming that either one is good for checking when power switch is on, I get no reading...now I checked power switch for continuity and it showed good, 'off' no reading, 'on' reading...
 

davenn

Moderator
With my meter set to 20k ohms, and leads connected one to 'neutral' and the other to 'hot', [doesn't say 'line'], at the 'power input socket', when I turn the 'power' switch to 'on', there is no reading...

hinting at a open circuit transformer but I don't see one .... maybe it's on the under side of that casing

...with one lead still on 'line/hot', and touching the 204/fuse, meter goes to '0.01' reading...[I get this reading regardless if power switch is on or off]...

that's just testing the short cct track between the input socket and the fuse

you main board photo is just too blurry to be of any use
do a couple of new photos of the main board ... SHARP ... look at them before you upload them .... if blurred rephoto before up loading
 
yes, 2 transformers underneath...one is directly underneath board 3 which has the power cord socket and F204 fuse...it has the P213 and P214 wires coming from it, plus 2 purple, 2 orange, and 2 red wires which go to main circuit board...the other transformer is on other end underneath with half a dozen wires going to middle sized circuit board, the board with no writing on it...20170407_045554.jpg View attachment 33103
 
yes, 2 transformers underneath...one is directly underneath board 3 which has the power cord socket and F204 fuse...it has the P213 and P214 wires coming from it, plus 2 purple, 2 orange, and 2 red wires which go to main circuit board...the other transformer is on other end underneath with half a dozen wires going to middle sized circuit board, the board with no writing on it...first image showing green, white, orange, black, etc wiresView attachment 33102

to get a halfway clear picture of large board, I had to take 2 pictures...[divide it in half]...hope this is better...20170407_063423[1].jpg 20170407_063230[1].jpg
 
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hinting at a open circuit transformer but I don't see one .... maybe it's on the under side of that casing



that's just testing the short cct track between the input socket and the fuse

you main board photo is just too blurry to be of any use
do a couple of new photos of the main board ... SHARP ... look at them before you upload them .... if blurred rephoto before up loading
welp...uploaded new pictures...may we continue please?...
 
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