Amiga 500: Bottom half of screen shows only garbage

03 August 2018, 22:34

Hello everyone,

Bought an Amiga 500 (Rev 6) off Ebay three days ago. Worked perfectly the first two days.
Today, though, the Amiga decided that it shall no longer show anything on the bottom half of my screen. Doesn't matter via which cable or port it connect (both mono and rgb). The bottom half of the screen is always garbage. Sometimes as in the attachment, sometimes a more solid color. And even more funky, the mono output plug does now also display some color (?!)

The only changes I did in the meanwhile was, that I connected a freshly bought "Boomerang B432" Gamepad to the Amiga (of course, when it was switched off) and a shiny new RGB -> SCART cable today.

Any ideas what went wrong? Hopefully the Gamepad or RGB cable doesn't have a problem and permanently damaged the machine.

Update: I also got the following Guru meditation when wiggling the RGB plug at the back of the computer: 80C01570

Hewitson · 04 August 2018, 18:41

As much as it's not recommended, wiggling the RGB plug shouldn't cause a guru.

Can you try the Amiga on a TV to rule out the monitor?

Toni Wilen · 04 August 2018, 18:58

TV most likely gets confused by Amiga's progressive mode and shows only half of the lines and the rest is uninitialized internal buffer RAM garbage. (More common side-effect is showing full height display but only updating it every other field)

Try setting WB to interlaced mode, does it "fix" the display?

03 August 2018, 22:34	#1
unic0der Posts: n/a	Amiga 500: Bottom half of screen shows only garbage Hello everyone, Bought an Amiga 500 (Rev 6) off Ebay three days ago. Worked perfectly the first two days. Today, though, the Amiga decided that it shall no longer show anything on the bottom half of my screen. Doesn't matter via which cable or port it connect (both mono and rgb). The bottom half of the screen is always garbage. Sometimes as in the attachment, sometimes a more solid color. And even more funky, the mono output plug does now also display some color (?!) The only changes I did in the meanwhile was, that I connected a freshly bought "Boomerang B432" Gamepad to the Amiga (of course, when it was switched off) and a shiny new RGB -> SCART cable today. Any ideas what went wrong? Hopefully the Gamepad or RGB cable doesn't have a problem and permanently damaged the machine. Update: I also got the following Guru meditation when wiggling the RGB plug at the back of the computer: 80C01570 Attached Thumbnails

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Kim Dot Com Documentary Shows an Amiga 500	Pyromania	Amiga scene	3	14 May 2018 13:55
Bottom of screen is missing	Iwantgames:)	support.Hardware	0	26 July 2015 00:35
WTD: Atari STE Parts - Bottom half of case & more	ElectroBlaster	MarketPlace	0	02 March 2011 16:23
Garbage on screen during boot	absence	Coders. General	6	20 February 2011 20:28
Wanted - A1200 Tin Shield Bottom Half - NEW	Peter	MarketPlace	0	15 September 2010 17:06

04 August 2018, 18:41	#2
Hewitson Registered User Join Date: Feb 2007 Location: Melbourne, Australia Age: 41 Posts: 3,773	As much as it's not recommended, wiggling the RGB plug shouldn't cause a guru. Can you try the Amiga on a TV to rule out the monitor?

04 August 2018, 18:58	#3
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,553	TV most likely gets confused by Amiga's progressive mode and shows only half of the lines and the rest is uninitialized internal buffer RAM garbage. (More common side-effect is showing full height display but only updating it every other field) Try setting WB to interlaced mode, does it "fix" the display?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)