Atari 800xl Looking for Help Trouble shooting.

Gaetznes

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Donor 2012, 2020
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I purchased this 800xl Hong Kong revision on the 16th. Lucky me, this version is all socket-ed. Unfortunately, I'm only getting a black screen with horizontal lines. Lines are white, greyish and occasionally with colours. Width and consistency of the lines vary. Pictures below


Things I've done in order to do some quick testing.

Verified all the logic ic's are working. I used this type of tester. http://www.pinitech.com/products/ic_tester.php

Resocketed all the ic's.

Checked the O.Crystal, 60hz, so verified its ntsc.

I've rotated the dram to see if anything different would occur. It didn't. I haven't done any piggybacking.

Double checked the power supply, all was well. Power to ic varies from 5.28v to 5.33v.

Attempted the Self-test to tell if I could at least hear the musical notes. At best I heard a single tone change in one of the test. Thought I'm assuming this was more likely the tv, not the computer. During test, image remained the same as displayed in image 1 through 3.


Other comments.

Sockets all look good. I have yet to re-flow, as a visual inspection revealed no cold solder joints.

Red Power light does come on

I don't own a oscilloscope

I don't own any cartridges

I haven't tested the capacitance of the capacitors yet. Though visually, their is no leaking or bludging. I own a cap wizard.

I do own a gq-4x, so replacing the basic with an eprom is an option. Once i find the pinout difference, if they exist.



So I'm curious if anyone has seen this before?


Images 1&2 are on lcd,

Image 3 is on a crt.

Images 4&5: two wires and a diode. I'm not familiar with the hard ware to know if this was factory or repair.


Removed all larger Ic's individually, to see if I could generate different images. Results

Image 6 CPU Removed

Image 7 Antic Removed

Image 8 Gtia Removed

Removal of Basic, OS, Pokey, Pia. This did not change the out put image from those of 1, 2 and 3.


I'm using a F connector to connect it to the tv's.

Note these lines are scrolling upwards.


Image 1
20139812_1986057704745142_2937796478072510107_n.jpg



Image 2
20106359_1986057708078475_4586581779229918029_n.jpg



Image 3
20155950_1986057738078472_5733370415385306421_n.jpg


Image 4
20139993_1986138181403761_1561639785483098826_n.jpg


Image 5
20228419_1986138198070426_7553821976468158799_n.jpg


Image 6 CPU
20155909_1986176338066612_6595078304601568813_n.jpg


Image 7 Antic
20155973_1986176344733278_7100985127045472299_n.jpg


Image 8 Gtia
20106382_1986176364733276_1082372808105403795_n.jpg
 
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