FDP - Forum

FDP Home Page / FDP Forum / FAQ's

The FDP is made possible by the following companies and individual members like you.
Please use the links below to show them we value their sponsorship.

Antique Electronics Supply
MOD KITS DIY
Jensen Loudspeakers
Apex Tube Matching

Sweetwater
WD Music
Yellowjackets Tube Converters
Amplified Parts

* God bless America and our men and women in uniform *
* Illegitimi non carborundum! *
If you benefit and learn from the FDP and enjoy our site, please help support us and become a Contributing Member or make a Donation today! The FDP counts on YOU to help keep the site going with an annual contribution. It's quick and easy with PayPal. Please do it TODAY!
Chris Greene, Host & Founder
LOST YOUR PASSWORD?
......................................................................

FDP Jam
Calendar

Find musicians
in your area!

Search the Forums

FDP Forum / Fender Amps: 1985 - Current / Cyber Twin power supply noise

Jehu

USA

Jul 17th, 2018 02:42 PM Edit Profile
I seemed to have a 60 or 120 hum suddenly appear. From what I understand, that's most likely a capacitor near the power supply. I have disassembled the whole thing. It's a head, not a combo. I ordered a cap tester from Amazon for this project ($30). I've never used one but it looks straightforward enough. When I got the main board out, I noticed that a 450V, 22uf cap was loose. The anode was completely corroded off. problem found. I went ahead and tested the rest of the caps in the vicinity of the power supply. I found another one that wouldn't give me a reading. It's fortunate that it's also a 450V, 22uf cap. I ordered some on Amazon because there are no longer any electrical supply stores in Reno.
https://www.amazon.com/gp/product/B075C81B4G/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
I've never replaced amp caps before. Am I getting the right ones? does the +/- rating matter for this application?

willie

Too Near Atlanta GA

Amp Tech Emeritus
Jul 17th, 2018 08:32 PM Edit Profile
The OEM parts (C127, C125, C143 and C148) are 22uF 450 VDC 20% tolerance. The one's you ordered should be okay, I would have suggested ordering from Mouser Electronics for a higher quality cap, but those should be okay. Be very careful unsoldering the defective caps and any residue or lead clippings left behind...as well as installation of the new caps. You have very sensitive PCB pads, high voltages and static sensitive digital/solid state components in that amp. We always disliked servicing the cyber series amps. Good luck and be careful.

w

FDP Forum / Fender Amps: 1985 - Current / Cyber Twin power supply noise

Reply to this Topic
	Display my email address Lost your password?
Your Message:
Link Address (URL):
Link Title:

Antique Electronics Supply	MOD KITS DIY	Jensen Loudspeakers	Apex Tube Matching
Sweetwater	WD Music	Yellowjackets Tube Converters	Amplified Parts


FDP Jam Calendar		Find musicians in your area!
	Search the Forums