Category Archives: Electronics Repair

Increase Laser Pickup Gain on Chrysler Infinity CD deck

topThe CD player in my Eagle Vision was slow to change tracks, didn’t seek to outer tracks, or handle my heavily scratched cd collection well… And, this finally led to some minor embarrassment – enough to drive me to fix it.

This CD player design was featured in basically all Chrysler vehicles through the 90’s (plus a earlier and later). The dash surround, at least in my Eagle, is attached with only speed clips – it pops right out when you gentley pry at the edges. Be careful detaching the wires since the harness doesn’t let you pull the deck out very far. This deck is grounded at one point only – through the strap bolted onto the back. Keep this in mind if you test with the cover off.

Now, if you’re smart, put a CD in, and seek to the last track before ejecting the CD and removing the deck – this will avoid most of the tedious manual seeking by finger tip. Remove the screws holding all the metal covers, including the heatsink side and ground bolt plate. Pull the top logic/RF board from the deck, exposing screws through the bottom board – remove these so that the bottom cover can be partially removed, giving access to the laser assembly. You will have to rotate the gear driving the slide the laser is mounted on in order to bring the laser close to the outside edge, exposing the gain potentiometer (see image below). Turn this pot clockwise to increase the laser gain – too much gain will burn out the laser, ruining your deck! You have been warned! I only had to turn the pot on mine a hair (about half a degree) to get the gain I needed – Unfortunately I couldn’t find solder points easily accessible with an ohm meter to measure the change the adjustment made.

laser potrffrom top digital

CA1010 Backlight Repair

ca1010-1When I got my Yamaha CA-1010 Amplifier, it worked quite well with the exception that most of the backlight did not work.  I promptly tore it down, checked the power consumption of a working bulb, and replaced the bulbs with LEDs with current limiting resistors.  Also, while inside, Ica1010-2 sprayed the controls with contact cleaner (isopropanol based) and followed with silicon lube to stave off oxidization.

From 2008 to 2010, I worked in a lab where my primary project was the upgrade of a helium dilution refrigerator so that RF measurements could be taken on a experimental package.  This system, previously used for helium experimentation, was massive.  Huge pumping speed with 6 or 8″ lines, double sealed mechanical pump, roots blower.  This is no small dilution fridge!

df1 df2 df3


PSP Power Supply Update

PSP (Original) Main Board (Power Supply)I was probing around a bit more and I’ve found the obvious problem, and it’s not the transistor. The power connector to tI can envision what happened now: an unregulated supply – works fine for just charging the battery, the current is low and the TPS65250 has a wide input voltage range. But, upon power up current demands go up, voltage drops, and this tiny connector melts because it can’t handle the current. It surprised me this would happen before the input fuse blew – bad design I guess, should have used a connector rated for higher current since the connector is on the supply side of the fuse. It took longer to find since I never suspected this, but, was fairly easy to fix. Next time check the simple things first.

NEC Versa LX secondary battery

battery2Battery uses weird Sony Energytec US103463 prismatic cells — haven’t found a suitable replacement cell — let me know if you have a source; until then, it’s filed under “battery”.

I love that laptop, and it’s great battery life. I kept asking myself why no-one makes new slower, low power laptops with new technology (except they’re moving towards it again with the XO and eeePC). The versa gave me 7 hours of portable computing (or more with standby), while most new laptops give you 3 hours. I couldn’t find anything smaller than the versa for a good price when I got a new laptop in 2005.

PSP Power Supply

PSP (Original) Main Board (Power Supply)Tom gave me his PSP after frying it by using the wrong powersupply. The micro fuses were okay, so onto the SMPS! It’s self contained – up in the top left corner in the picture, but, on the other side of the board. I didn’t take a picture of that size for some reason. So, this supply is based on a Texas Instruments Power Management IC, TPS65250. Anyways, closest datasheet I could find online was for the TPS65050 series. I assume the rating are simply a bit different, or this is OEM’d. I’m thinking right now that the main switching transistor is shot…and since those SMD transistors are basically impossible to identify – since they never seem to have any text on ’em – I just pull random ones off of old broken computer motherboards and assume they’re close enough….they all have been so far.