Help fixing Vector-06c

[KTSerg]

Hello,
First off my apologies, I'm in the USA and I only speak English.
A long time ago I bought a BK-0010 and a Vector-06c off of Ebay. The BK-0010 works fine but the Vector has lots of problems. I've already replaced the CPU and two flipflop chips so at least it boots, but now I'm stuck.
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Hello.
I am writing through an online translator.
The checkered picture when turned on is a good sign.

If the boot grid does not appear, the memory may be defective.

Can I find the serial number and release date of this computer?
A relay seems to be installed near the speaker, this is an exceptional rarity.