need fender frontman 25r help

[MBDiagMan]

Do you have a schematic you can send me? It will be across the rectifier output.

[harpspitfire]

not really- steve posted a good link, 2nd post in this thread. thats probably all a tech would need, in my case, i would need more visual assistance

[MBDiagMan]

Harp,

Okay, I hadn’t noticed the link. I opened up the schematics, but they are not sharp enough for me to read. There are four capacitors in the rectifier circuitry that you need to check, but I can’t read the designator to tell you which ones. If we had readable schematics and parts diagram I could point you right to it. I will try to remember to find something readable later in the day.

I can’t find a readable schematic. In the lower left of the one in the link, there is a transformer. Above the transformer is the rectifier section in the far left. There are four capacitors in that section that need to be checked. If I had a readable version I could get their designator, such as C1 as an example, and then look for C1 on the parts diagram.

Hope this helps. If you find a readable schematic version, post it or PM me and I will be happy to help further.

[MBDiagMan]

Do you know what an electrolytic capacitors looks like? If you just tested the electrolytics, you could probably find the culprit. It appears that they are mounted to the circuit board standing on their ends. You need good soldering skills to disconnect on end for testing.

https://www.walmart.com/ip/Nichicon-...&wl13=&veh=sem

Look at this link to see what an electrolytic looks like. A can with a groove around one end. Not all of them have both leads out of the same end, but that is the shape. This type capacitor is polarized meaning there is a positive end and a negative end, so it must be connected properly or it will blow up like a firecracker after a few seconds of reverse voltage.

Hope this helps.

[harpspitfire]

ok, on parts diagram, i know its small and blurry- there's a zoom tab (or enlarge) anyway- then a big circle appears on the screen, thats a movable magnifier, its pretty neat

[MBDiagMan]

Harp,

It must be on a different viewer on my iPad. Try as I might I can’t find a zoom feature. I will keep working on it.

[MBDiagMan]

Very frustrating! If I could see the details I could help. Is the hum occurring on both channels?

[harpspitfire]

well, on the drive channel, its playable- i mean it really isnt bad, the clean channel is the issue, frankly, i went to look at fender champion 30 today, that amp also had bad clean channel buzz, though not as bad as mine, i think for right now, ill just play it as it is unless it gets worse, i'll start saving for a better amp in the meantime