Question about Adcom GFA-5500 2-Channel Amplifier

2 Answers

My adcom gfa5500 .most of its output mosfets are shorted.

I m able to get the output mosfets. BUT,when i check other components,i found out the value of R 23 of the left channel is different from the rigt one.since i dont have the schematic.i neeeeed help!!!!

Posted by on

  • Scott Frye
    Scott Frye May 11, 2010

    Hi...

    I have the diagrams for the MarkII
    What is R23 connected to?
    I can cross it to my docs.
    Thanks

    Also, ADCOM gave me free docs.
    Ask them nicely and they'll get you some.


×

2 Answers

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 12 Answers

I give you the schematic

Posted on Jun 25, 2015

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Adcom Master
  • 4,946 Answers

The colour code or the value it states on R23 should give you the reading you will see on a test meter on the Ohm setting. If the value doesn't match the colour code of the resistor then you should replace it. It's best to take any resistor out of the circuit to test as strange readings can be caused in circuit. The same applies to the left channel one. Ohm meters are not expensive if you don't have one and can be got from various places that sell electronics parts etc. Some car part dealers sell them. They are a worthwhile investment and can be used for many types of problem.
It's likely that it's a basis resistor and failed when the power jobs went.

Posted on Oct 22, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

How to fix sony 29'' wega, using irf 614 mosfet. mosfet is short


Check all the other component on board, associated with this MOSFET cirlcuit. Especially shorted zener diode, capacitor/s etc: Never replace an other FET, without check all the related component. It too will fail. Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
Type in this key phrase " my service table today " in the search box at the top right of the display window of the home page, to get gathered some pages which has the details of practical experiences to the author of that site.

Nov 17, 2015 | Sony Televison & Video

1 Answer

My PIXMA MP970 printer abruptly lost power. is it due to fuse problem and where is the fuse box?


Dear
The printer has the step down SMPS which supply the low voltage (generally 24V DC to the other component. It contains high voltage risk also the high frequency. Sound knowledge is required while repairing the SMPS also appropriate precaution. If somebody is present having electrical knowledge during repair is better.

First disconnect the electricity supply cable from the printer
open the smps, check visually for any physical abnormality of individual component, then check the fuse for open,if its open check the MOV,mosfet,capacitor,bridge/zener diodes for short if found replace with same value,
take a series lamp of 15W incandescent bulb, connect the smps, check the voltage at secondary output. utmost care should be taken with attention of co-worker while checking live circuit.
If there is no voltage, check primary component at area of PWM IC /replace PWM ic (smd).

Again FATAL ELECTRICAL SHOCK AND FIRE MAY HAPPEN IF CARE NOT TAKEN.

Thanks.

Feb 13, 2015 | Canon PIXMA MP970 InkJet Printer

2 Answers

I have a Denon PMA 500V amplifier. all of the output fuses were blown so I replaced them but the unit still doesn't work. Any suggestions?


hi.
Did you checked balanced impedance?load speaker impedance vs PA output?or PA might over driven,causing a trouble on the pre-amp to power amp circuits and components damage,
need to recheck related components on the pre-driver up to main output section,

Note: That,blowing of fuses with the same rating is an indication of trouble/shorted in a circuits that driven on it,

Thanks and good luck

microhit

Jun 01, 2011 | Denon PMA-2000R 2-Channel Amplifier

2 Answers

Power supply HP-A3108F3P Line rectified voltage is good, 310 V. No output voltages, no voltage on UC3843, no oscillation. Switching Mosfet is ok. Need help, thanks.


That could be a problem on secondary side. Shorted rectifier diode.

Please do check start up resistor of uc3843, I think its on pin 7 with 110Kohms or 56Kohms value for 220VAC or 110VAC supply input respectively. Open or change value, it is a fusible resistor. If open do check other components for defects. Don't substitute a common resistor on this one. Datasheet could help you alot.

A word of warning, the voltage may bite and enough to kill. So take necessary precaution, if in doubt let the tech handle it. Or buy a new one.

Oct 18, 2010 | IBM HPA3108F3P 310Watt Power Supply

1 Answer

I need MOSFET transisitor NF43AT , where I can found it.


That Mosfet is probably porprietory from Sports Art , But I would check the bridge rectifier I've had quite a few short out and make it appear that the Mosfet is shorted. Any of the Parts houses would carry that component.

Mar 12, 2010 | Sportsart 6300 Treadmill

2 Answers

Kicker zr600 smokin havent even bumped yet today


Well it seems to me that the pictures of this amp show green ATC fuses which would be 30 amp fuses. What is your inline fuse from the battery? 40 amp fuses for the amp is too much current for the amps powersupply. If there was a short in the powersupply the max ammount of current that it could draw would be larger than designed to handle therefore damaging the amp.

Jan 02, 2010 | Kicker ZR600 Car Audio Amplifier

1 Answer

Schematic drawing of Adcom GFA-5300/how to check driver circuits


The driver circuits should be just before the outputs in the circuitry. The easiest way to check this circuit is to remove the outputs and turn on the unit. Measure each of the transistor pads relativce to ground for DC voltage. You should see the following: B+,0.6V (or 1.1V), and 0V on one transistor and negative values on its compliment. If you have questions, measure the pads and post the measurements here. In some cases the output transistor needs to be in place to get the values above, so if yours don't measure that way, just post what you get and we'll continue from there.

Dan

Dec 08, 2009 | Adcom GFA-5300 2-Channel Amplifier

1 Answer

Component Video Inputs/Outputs Not Behaving as advertised


I have had this problem in the Field with a Client. I had fixed it by going into the ADCOM menu and Resetting ALL of the Inputs and output for the Devices. You have to select everything you need, then exit out of the Menu, SHUT OFF the ADCOM, WAIT about 10 secs, then turn it back on. Or Else it Does Not SAVE Properly! Weird. If you can not see the Menu on the TV Screen then try to hook up a Composite (Yellow) cable from the ADCOM to the TV and select the TV input to make the Changes. I really hope this helps out it sounds like an Evasive problem which is hard not being in front of the Equipment!

Nov 29, 2008 | Adcom GTP-860II

4 Answers

ADCOM GFA 5802 POWER AMP NO SOUND, BUT POWERS UP.


Remove the output transistors and measure each of the sets of 3 pads and report the voltage readings here. I suspect that you have either a blown driver circuit or output transistors. The voltage readings will give me an idea on where to start looking for specifics.

Thanks,
Dan

Nov 11, 2008 | Adcom GFA-5802 2-Channel Amplifier

1 Answer

Sanyo ST-21G1 dead set


There should be a small valued cap in the primary side (22ufd?) at 250V. Check that. Also, look for other small caps int he range of 2.2ufd with 200V ratings in the same general area.
Dan

May 07, 2008 | Televison & Video

Not finding what you are looking for?
Adcom GFA-5500 2-Channel Amplifier Logo

Related Topics:

417 people viewed this question

Ask a Question

Usually answered in minutes!

Top Adcom Audio Players & Recorders Experts

 Grubhead
Grubhead

Level 3 Expert

4946 Answers

Computer Links

Level 3 Expert

2385 Answers

Greg Cann
Greg Cann

Level 3 Expert

1114 Answers

Are you an Adcom Audio Player and Recorder Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...