Sony GDM-F500

The problem is a constant pincushion effect that is concave at left and right sides of the screen. I have the schematics for this model. Any ideas on what might be causing this? A bad cap? I'll try some freeze spray on a few areas.

jimbo

Reply to
Jimmy Martin
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IC007 CXA2043Q is a common failure - results in all sorts of deflection-related faults.

Wayne

Reply to
Wayne

This is a 48 pin surface mount chip. What level of difficulty is it to desolder and resolder? Can I use a 30 watt fine tip iron and solder wick for this job? I found the chip for $32.99 at

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I think I will order it and give it a try.

Jimbo

Reply to
Jimmy Martin

I have done a few of these - just finished one this week. The method I use to remove the IC is on page 9 of the REV 1.3 pdf at

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(the procedure for Small Outline IC's) I find that enameled wire that is .010 dia works best.

I've done these with a simple 25 watt weller iron with a very fine tip, that I filed myself, as my cheapie iron does not have a fine enough tip commercially available for it. Before I did my first one, four years ago, I practised removing sm ic's from old motherboards. Replacing the CXA2043Q requires above average soldering skills, and you don't want to damage any of the very fine tracks that the ic is soldered to, so if this is your first attempt, better practise ahead of time and perfect your tecnique.

In the ones I've done, a number of the electrolytics near the IC have to be removed to give enough room to do the job successfully. On all the Sony pcb's that I've done, the pcb's are through-plated, and you have to really careful removing the electros so as to not damage the pcb. This also requires a good tecnique. What has worked for me is this, for each electro.

1 - add a small amount of flux to the electros two solder pads on the bottom of the pcb 2 - use solder wick to removes most of the obvious solder. You want to end up at this point with a partially open (from the bottom of the pcb) through-plated hole. The electro will still be firmly soldered to the board, however. 3 - while applying heat to the lead of the electro, again from the bottom of the pcb, use a very small jeweller's screwdriver to bend the leads of the electro up and away from solder connection to the bottom of the pcb 4 - use needle nose pliers to gently grab the leads of the electro and bend the leads close to straight up and down, i.e., perpendicular to the pcb.

In all cases in the process, you have to be careful to not use excessive mechanical force or apply too much heat. Some of the plated through holes are very small diameter and some of the tracks are very thin. Easily damaged!

5 - now lightly resolder the two electro leads to the pcb, from the bottom. the idea here is to add enough solder so the next step works well. 6 - what you now need to do is to use a finger from one hand to (gently) rock the electro alternately from one side to the other while applying heat to the appropriate lead with your iron, from the bottom of the pcb. each gentle push in one direction on the top of the electro on the top side of the pcb while heating/melting the solder on the appropriate lead from the bottom of the pcb will result in fairly quickly levering/extricating the electro out of the pcb, with the pcb unharmed. 7 - once the electro is out, then use your solder wick to remove the remaining solder in the through-plated hole. usually this can be done from just the bottom, but sometimes going to the top side of the pcb is also required. Also you may have to add a bit of solder or flux to facilitate removing enough solder from the hole to be able to insert the electro (new or reused) for reinstallation after the CXA2043Q has finished installation.

The biggest thing I learned while practising both of the tecniques (IC removal/installation and electro removal) was to be gentle and not overdo the heat with my soldering iron. The job can be done with simple tools, but if you're not experienced, be sure you practice ahead of time. Tracks are easily damaged!

Wayne

Reply to
Wayne

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