Q1: A 2xx POST error code indicates a problem with:

ANS:A - RAM or ROM

2xx POST error code...
2xx RAM Errors
201 memory test error
202 memory address error (Line error 0 - 15)
203 memory address error (Line error 16 - 23)
216 motherboard memory

Memory
2XX
201 Memory (address indicated in hex)...
if the post find an error with the RAM, it would not boot at all and it can generate sound code beeps.
01x Undetermined problem
02x Power supply
1xx System board
2xx Memory
3xx Keyboard
4xx Monochrome display adapter
PS/2 system board parrallel port
5xx Color Graphics Adapter (CGA)
6xx Floppy drive/adapter
7xx 8087, 80287, 80387 math coprocessor
9xx Parallel printer adapter
10xx Alternate parrallel printer adapter error
11xx Asynchronous communications adapter
PS/2 System board async port
12xx PS/2 dual async adapter
13xx Game control adapter
15xx Synchronouse data link control (SDLC) communications adapter
17xx Fixed disk (hard drive)
18xx I/O expansion unit
20xx Binary synchronous communications (BSC) adapter
21xx Alternate binary synchronous communcations adapter
30xx Primary PC network adapter
31xx Secondary PC network adpater
73xx 3.5 inch external disk drive
86xx PS/2 pointing device
100xx PS/2 multiprotocol adapter
104xx PS/2 ESDI fixed disk
202 Memory address (address lines 00-15)
203 Memory address (address lines 16-13)
204 Memory remapped due to error (run diagnostics)
205 Base 128K memory error; memory remapped
207 ROM failure