Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: RockinRick on October 10, 2014, 09:43:16 PM

Title: Pignose Hog 20
Post by: RockinRick on October 10, 2014, 09:43:16 PM
i picked up a Pignose Hog 20 for $100.00 at Goodwill.  It didn't come with a power converter so I purchased one for $16.00.  The power light does not come on so i assume it not charging up.  What is the next step and is it worth putting anymore into it?
Title: Re: Pignose Hog 20
Post by: Roly on October 11, 2014, 06:24:06 PM
Assumptions are something we try to avoid.  Quite literally anything could be wrong at this stage and we need to narrow it down and eliminate all the usual suspects until the right one is found.

Quote from: RockinRickWhat is the next step

First up you will find the circuit for your amp posted here (with thanks to @diyfalk);
http://www.ssguitar.com/index.php?topic=1166.msg21280#msg21280 (http://www.ssguitar.com/index.php?topic=1166.msg21280#msg21280)

Quote from: RockinRickpower converter

a) is it the right voltage?  (12 volts DC)
b) does it have sufficient current capacity?  (1500mA/1.5amp or more)
c) is the connector the correct polarity? (+ve inner; there is no standard)
d) the amp has a 2.5 amp fuse - have you checked it for continuity (with a multimeter)?

If these all check out, then according to Pignose owner @highplainsdrifter it works without the batteries connected, so if you are sure you have the right voltage and polarity, disconnect one of the battery terminals and see if that makes any difference (the batteries could be shorted internally)

e) does it show any signs of life on the power supply with the battery disconnected?


Quote from: RockinRickis it worth putting anymore into it?

This is an impossible question since we currently know next to nothing about your particular amp, the state of your finances, your electronics skills and facilities, and how tenacious you are.

Fault diagnosis normally only costs you time probing around with a multimeter.  As professional techs we don't use the "scattergun" approach of replacing all the caps, resistors, transistors, knobs or whatever because it's expensive and, more importantly, doesn't work as a faultfinding method.  At the moment we could be looking at anything from a smoking ruin (writeoff) to a dirty connector (trivial), however the odds are in favour of it being down the minor/trivial end of the scale.


Quote from: CarlIt uses 2 six volt 4AH SLA batteries, wired in series.

Sealed Lead-Acid batteries are great components, but they do have a finite life and can be a bit pricy to replace when needed, so are a typical reason for equipment fitted with them to be disposed of.

Another common fault with chipamps is the failure of the chipamp itself.  The one fitted to this amp is discontinued but some suppliers still have stocks.  Worst case they seem to be about $15 - if you actually need one.  (Caution: there are two different versions, one with straight leads and one with bent leads.)

In the thread referenced above we also discovered a design fault that can easily be modded by adding a couple of of cheap components.

So first we find out what is actually wrong, then we take Berlin.

Please post answers to the questions above.