It is currently Mon Mar 16, 2020 11:40 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 6 posts ] 
Author Message
Post subject: HotRod Deluxe Test point voltages and issues!!
Posted: Fri Dec 22, 2017 5:43 pm
Offline
Hobbyist
Hobbyist

Joined: Fri Nov 11, 2016 8:16 am
Posts: 10
I have the USA version. Board is marked FMIC 1996. Can someone please list the correct voltages for all test points.......like 1 through 30 or 40.....however many there are. I corrected R78 / R79 by moving off the board. Amp fizzes out when strumming hard after 15 seconds. Volume drops out. Strum lightly and it comes back. Same result when plugging the guitar into the power amp in jack of the effects loop. Changing the tubes did nothing. I keep coming across information that it might be grid screen resistors for the 2 power tubes? I would like to check all voltages to track down the problem. Any help would be great!


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: HotRod Deluxe Test point voltages and issues!!
Posted: Sat Dec 23, 2017 4:16 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14047
Location: Province de Québec, Canada
It look a solder issues, re-heat all solder.
Check for good contacts on all connector, voltages reading are useless

Schematic and chassis is here with test points;

http://schems.com/bmampscom/fender/HotR ... _Rev-B.pdf

Look same issues as you here;

https://forums.fender.com/viewtopic.php ... 52&start=0


Top
Profile
Post subject: Re: HotRod Deluxe Test point voltages and issues!!
Posted: Sat Dec 23, 2017 9:41 am
Offline
Hobbyist
Hobbyist

Joined: Fri Nov 11, 2016 8:16 am
Posts: 10
Thank you for the test point voltages which are very important in finding the culprit. Much appreciated


Top
Profile
Post subject: Re: HotRod Deluxe Test point voltages and issues!!
Posted: Sat Dec 23, 2017 9:45 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14047
Location: Province de Québec, Canada
AshHole wrote:
Thank you for the test point voltages which are very important in finding the culprit. Much appreciated


Good luck :)


Top
Profile
Post subject: Re: HotRod Deluxe Test point voltages and issues!!
Posted: Sat Dec 23, 2017 3:42 pm
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
Screen grid resistors can be taken out when a power tube gets shorted. They usually discolor the code bands or blacken the resistor body.
The switch contacts on the extension speaker jack can also cause a hi power fizzle. The speaker cables are also known to go bad at the jack.
The cathodes of the power tubes ground through the one ohm resistor where you measure bias. Make sure this is in good shape and not damaged from a shorted tube.
Any tube that doesn't have a stable ground path for the cathode will fizzle out.
A tube that gets too much dc on the grids will fade out and pop back in on power down.


Top
Profile
Post subject: Re: HotRod Deluxe Test point voltages and issues!!
Posted: Tue Dec 26, 2017 9:09 am
Offline
Hobbyist
Hobbyist

Joined: Fri Nov 11, 2016 8:16 am
Posts: 10
There is a guy on ebay that sells an HRDX fix kit. I bought that and some 100k resistors to address the most common issues. I'm assuming the kit will address everything discussed in this thread so far.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: