No power to tube fan?

[ATR1]

Hello,
Mark V 90w combo amp.
I noticed yesterday my fan stopped working cooling the tubes. Watched video on fan replacement. I ordered a fan. This morning removed the fan in question and tested with a 9v battery.
Fan was working fine?
Need help to troubleshoot why my fan stopped getting power?

Thx

 

[rarebitusa]

Is the fan switch off? If not, then perhaps check the fan leads from the unit for a voltage between 9-12vdc. If it's low then maybe there's a problem the 12v circuit which the fan voltage is tapped from. It's been a known issue on V:90s that the bridge rect diodes can fail.

 

[ATR1]

Thx.
I have no lights on front of amp also. May have to send in to boogie.

 

[rarebitusa]

Well that a strong clue it's the low voltage diode issue. This is a typically a straightforward fix to replace the 4 bridge rect diodes.

If you can find one within driving distance. For this issue I'd think an authorized Mesa repair shop can take care of that for you.

Find a Mesa Repair Shop

 

[ATR1]

Thank you my friend! I will search out a amp tech or send back to MB.